High-frequency-link power-conversion system having direct double-frequency ripple current control and method of use
First Claim
1. A method for reducing a double-frequency ripple current disturbance introduced by an inverter load coupled to a fuel cell system, the method comprising:
- generating, by a first proportional-resonant controller, an output having a first double-frequency component of a phase shift angle between the active switches on a low voltage side (LVS) and a high voltage side (HVS) of a fuel cell system;
generating, by a proportional-integral controller, an output having a dc component and a second double-frequency component of the phase shift angle between the active switches on the low voltage side (LVS) and the high voltage side (HVS) of the fuel cell system; and
offsetting the first double-frequency component generated by the first proportional-resonant controller with the second double-frequency component generated by the proportional-integral controller to reduce a double-frequency ripple current disturbance introduced when an inverter load is coupled to the fuel cell system.
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Accused Products
Abstract
A direct double-frequency ripple current control in a two-stage high-frequency-link (HFL) based fuel cell converter that can achieve low-frequency ripple free input current without using large electrolytic capacitors is provided. To eliminate the double-frequency ripple current disturbance introduced by the single-phase inverter load, a proportional-resonant (PR) controller is developed to achieve an extra high control gain at designed resonant frequency. This high gain can be viewed as the virtual high impedance for blocking the double-frequency ripple energy propagation from inverter load to fuel cell stack. More particularly, the proposed control system can realize the utilization of all capacitive ripple energy sources in the system by regulating all the capacitors to have large voltage swing and the voltage swing is synchronized to keep real-time balancing of the transformer primary-side and secondary-side voltages. As a result, the zero-voltage-switching (ZVS) operation for all switching devices in the dc-dc stage can be guaranteed.
6 Citations
20 Claims
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1. A method for reducing a double-frequency ripple current disturbance introduced by an inverter load coupled to a fuel cell system, the method comprising:
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generating, by a first proportional-resonant controller, an output having a first double-frequency component of a phase shift angle between the active switches on a low voltage side (LVS) and a high voltage side (HVS) of a fuel cell system; generating, by a proportional-integral controller, an output having a dc component and a second double-frequency component of the phase shift angle between the active switches on the low voltage side (LVS) and the high voltage side (HVS) of the fuel cell system; and offsetting the first double-frequency component generated by the first proportional-resonant controller with the second double-frequency component generated by the proportional-integral controller to reduce a double-frequency ripple current disturbance introduced when an inverter load is coupled to the fuel cell system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for reducing a double-frequency ripple current disturbance introduced by an inverter load coupled to a fuel cell system, the system comprising:
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a first proportional-resonant controller configured for generating an output having a first double-frequency component of a phase shift angle between active switches on a low voltage side (LVS) and a high voltage side (HVS) of a fuel cell system; a proportional-integral controller configured for generating an output having a dc component and a second double-frequency component of the phase shift angle between the active switches on the low voltage side (LVS) and the high voltage side (HVS) of the fuel cell system; and circuitry for offsetting the first double-frequency component generated by the first proportional-resonant controller with the second double-frequency component generated by the proportional-integral controller to reduce a double-frequency ripple current disturbance introduced when an inverter load is coupled to the fuel cell system. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A system for reducing a double-frequency ripple current disturbance introduced by an inverter load coupled to a fuel cell system, the system comprising:
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a first proportional-resonant controller configured for generating an output having a first double-frequency component of a phase shift angle between active switches on a low voltage side (LVS) and a high voltage side (HVS) of a fuel cell system; a proportional-integral controller configured for generating an output having a dc component and a second double-frequency component of the phase shift angle between the active switches on the low voltage side (LVS) and the high voltage side (HVS) of the fuel cell system; a second proportional-resonant controller configured for generating a duty cycle having a dc component and a ripple component; and circuitry for offsetting the first double-frequency component generated by the first proportional-resonant controller with the second double-frequency component generated by the proportional-integral controller to reduce a double-frequency ripple current disturbance introduced when an inverter load is coupled to the fuel cell system. - View Dependent Claims (20)
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Specification